Development of a Monocyte Activation Test as an Alternative to the Rabbit Pyrogen Test for Mono- and Multi-Component...

Area of Science:

• Vaccinology
• Immunology
• Microbiology

Background:

• Generalised modules for membrane antigens (GMMA) vaccines are derived from Gram-negative bacteria and contain pyrogenic components.
• Traditional pyrogen tests like the rabbit pyrogen test (RPT) and bacterial endotoxin test (BET) have limitations for inherently pyrogenic products.
• Controlling pyrogenicity is crucial for vaccine safety to prevent adverse reactions like fever.

Purpose of the Study:

• To adapt and validate the monocyte activation test (MAT) as an alternative to the RPT for pyrogenicity assessment of *Shigella* GMMA-based vaccines.
• To evaluate the suitability of different MAT methods, specifically focusing on the reference lot comparison test (Method C).
• To establish the utility of drug substance as a reference material for safety testing of GMMA drug products.

Main Methods:

• Adaptation of the European Pharmacopoeia's monocyte activation test (MAT) Method C (reference lot comparison test).
• Evaluation of MAT Method C using reference materials for mono- and multi-component *Shigella* GMMA vaccines.
• Demonstration of drug substance as a suitable reference material for safety testing.

Main Results:

• MAT Method C was successfully adapted and validated for monitoring pyrogenicity in *Shigella* GMMA vaccines.
• Parallelism and consistency were achieved using defined reference materials.
• The drug substance proved to be a reliable reference material for the matched drug product.

Conclusions:

• The monocyte activation test (MAT) is a suitable alternative to the rabbit pyrogen test (RPT) for assessing the pyrogenicity of GMMA-based vaccines.
• The validated MAT method and use of drug substance as reference material can aid in the batch release of GMMA vaccines.
• This approach can be extended to other GMMA-based vaccines in development, improving safety testing protocols.